Self-flaring pipe coupling



Dec- 12, 1950 s. GuARNAscHELLl 2,534,198

SELF-FLARING PIPE COUPLING Filed March 11, 1947 WOR/vnf Patented Dec. 12, 1950 y ASELF-FLARING PIPE COUPLING Stephen Guarnaschclli, Naugatuck, Conn., as-

signor to The Brockway Company, Naugatuck, Conn., a corporation of 'Connecticut Application March 11, 1947, Serial No. 733,843

3 Claims.

This application relates to an improvement in couplings for` threadless ductile pipe, tubing, conduit or 'other elongated tubular ttings (hereinafter called pipe) particularly couplings of the type adapted to form a flare on the pipe when the coupling or connection lis made up.

It has been known for many years to make connections using ductile threadless pipe having apre-formed iiare on the end thereof, by using a pair ofcouplingv members interconnected by suitable draft means, and having a pair of flareengaging and clamping surfaces adapted respectively to clamp against the rear and front surfaces of the flare on the pipe so as to clamp the same in leaktight engagement.k

In order to assemble installations in which random lengths of pipe are requiredit was necessary to employ a flare-forming tool to flare the. endof the pipe onthe job after it was cut the desired length. The necessity of having such tools availablepresented a substantial inconvenience for the workman. Often when it was necessary to make emergency repairs or replacements in existing installations, such tools were not immediately available and serious lossesin time and expense were caused.

It has been proposed heretofore-to manufacture selfflaring couplings wherein the coupling parts themselves are adapted to form a flare on the pipe incidental to makingv up the connection, but such couplings generally-require special construction often unavailable or unsuitable for use in installations including the common forms of couplings `usedwithv pre-flared pipe.

In accordance with this invention, standard forms of couplings :are modihed in a simple and inexpensive manner to" render them capable of forming a flare on the end of a length of ductile threadless pipe incidental to making up the connection, such modification interfering in noway with the use Vof the .coupling in the conventional manner for connecting pre-flared pipe. Thus, couplings including the modification of my invention are adapted for usein all kinds of installations, insuring the possibility of making rapid installations, repairs or replacements with a minimum of inconveniene or loss of time, and without the necessity `of maintaining a supply of special tools for carrying out the job.

Thus, the couplinglin accordance with my invention, comprises a pair of coupling members, one of which encircles'a length of ductile threadless pipe behind the end thereof, said coupling member having a-flare-'engaging and clamping surface onitsleading end,adapted to engagethe rear side of a hare on the end of the pipe. The other coupling member has a hare-clamping projection, usually of conical form, for engaging the front 'of the ilare on the end of the pipe. The two members are interconnected by draft means, such as complementary threads on the iiareclamping members themselves, or on a draft member or members associated with them, for advancing the flare-engaging surfaces into nareclamping relation with the flared end of a pipe.

In accordance withmy invention, I provide in the coupling member which is adapted to encircle the pipe behind the flare, means for anchoring said member to the ductile pipe against axial displacement thereon, said means being independent of the connecting or coupling operation of the coupling or draft members; preferably, said independent clamping means comprises one or more set screws disposed in lateral apertures in the coupling member, which are adapted to bite into the wall of a pipe inserted` through the bore of. the coupling member. Preferably, the set screws, when tightened against the pipe, are flush or level with the outside surface of the coupling member or below the level of said surface, so that they do not interfere with any other part of the coupling.

When a coupling member comprising the aforesaid modication, is used with pre-flared pipe, the set screws can be removed or left loose in their apertures withoutinterfering with the normal flare-clamping operation of the coupling. However, whenathe pipe is not pre-flared, the coupling member comprising the independent anchoring means, particularly the set screws, is placed over the end of the ductile pipe to be connected, and positioned thereon so that an end portion of the pipe,suflicient to form the requiredflardprojects beyond the leading end of the bore ofsaid coupling member adjacent the are-clamping surface thereof. The independent anchoring means or set screws are tightened against the pipe so as to hold the coupling member rmly in place against axial displacement. The opposite coupling member, having the conical projection, is then advanced by operation of the draft means toward the projecting end of the pipe. When it engages the end of the pipe, it is forced into the same causing the pipe to flare thereover. Final tightening of the draft means clamps the resulting ilare between the clamping surfaces of the respective coupling members to form a leaktight connection therewith.

When it is impractical to permit the pipe to rotate relative to the coupling member having the conical projection, a draft member is preferably provided which engages the opposite coupling member encircling the pipe, but which is rotatable relative thereto so as to advance the anchored nare-clamping members and the pipe toward the projecting end of the opposite coupling member, without requiring corresponding rotation of the pipe.

Should the coupling be constructed without the foregoing feature, and it is nevertheless necessary to connect un-flared pipe by means of suitable coupling members, the two members can be first used as flare-forming tools before installation of the pipe, and then, after the flare has been formed, theset screws or other anchoring means can be released or removed, and the coupling employed in the usual manner for connecting the pipe which is now pre-flared.

My invention will be more fully understood from a number of preferred embodiments thereof, hereinafter described with reference to the accompanying dra-wings, wherein:

Figure 1 is an axial cross-section of a. coupling in accordance with my invention, assembled preparatory to the flare-forming operation;

Fig. 2 is an axial cross-section of the coupling of Fig. l after the same has been made up;

Fig. 3 is an axial cross-section. of a connection made with standard coupling members, modied to embody my invention; and

Fig. i is likewise an axial cross-section of a connection with another type of standard couin a threaded orice of a passage I3 in a structure I4. The fitting Iii has a longitudinal bore I5 extending therethrough for communicating with the passage I3 and with a length of ductile pipe I t to be connected to the front end of the fitting. The front end of the ntting has external threads Il, and terminates at a conical projection or nose I8, adapted to engage and be clamped against the front side of the flare on the end of' a piece of ductile pipe.

The coupling further comprises a ferrule I9, having a bore adapted slidably to receive the threadless ductile pipe I t, and having a reentrant conical dare-clamping surface 2S at its forward end, for engaging and clamping against the rear side of a flare on the end of the pipe I6. The coupling further includes a draft member or hollow nut 2l having a cavity 22 therein adapted to receive the ferrule Iii at its inner end, and having internal threads 23 at the outer end of said cavity for engaging the threads I'I on the front end of the fitting Iii. At its rear, the nut 2! has a flange or shoulder 2li surrounding an aperture adapted to receive the ductile pipe I6, said shoulder engaging the rear end of the ferrule I@ to advance the same toward the conical projection I8 of the tting IS when the nut is threaded on to the leading end of said fitting.

In accordance with my invention, the ferrule I9 has a number or lateral threaded apertures therein in which set screws are disposed. In order to use the coupling for flaring and connecting the pipe i5 to the ntting iii, the ferrule i8 is slipped over the end of the pipe I5 so that an end portion 22 of the pipe, adapted to fom/n the desired nare, projects from the bore of the ferrule adjacent the reHentrant conical flareclamping surface 2?. The set screws 25 are tightened so that theyiiindent or bite into the wall of the pipe I6, thus securely anchoring the ferrule I9 against axial movement on the pipe. When thus secured, the outer ends of the set screws 25 are hush or below the level of the outer surface of the ferrule I9, so that they do not interfere Awith insertion of the ferrule into the base of the cavity 22 in the nut 2l.

The nut 2| is positioned on the pipe I6 behind the ferrule Ill, and is advanced along the pipe until the ferrule is seated in the base of the cavity 22 in the nut. The latter is then threaded onto the leading end of the tting I6, advancing the ferrule I9 together with pipe I5 toward the conical flare-clamping surface I-l on the tting IEB. The nut 2i rotates freely relative to the ferrule i9, so that there is no tendency during the threading operation to rotate the pipe i6. As the leading end 2e of the pipe i5 engages the conical surface i8 on the fitting, and advancement is continued, the pipe end 2'5 rides up over said conical surface and is flared thereby, as shown in Fig. 2. Final tightening of the nut 2I clamps the flared end 22d of the pipe firmly between the surface 22 on the ferrule and the conical end surface is on the tting, forming a leaktight connection between the iitting I@ and the pipe I8.

Applications of my invention to standard types of ttings are shown in Figs. 3 and 4. In Fig. 3, the coupling comprises only two coupling members, the ntting 22 including a hollow nut portion having an internally threaded cavity 2E- therein with a conica-l iiardengaging projection 23 at the base of the cavity. A bore 3S extends from the rear end of the tting to the end of said projection, and is adapted to communicate with passage I3 in the structure Ill. The rear end of the fitting 2i' has a threaded portion 3l (like fitting Iii) for securing the same in the orifice of passage I3. The opposite coupling member is a sleeve 32 having a bore adapte-:l to receive the threadless ductile pipe 33, and having external threads 31% f r engaging the internal threads in the cavity 2B. At its leading end, the sleeve 32 has a re-entrant conical flareengaging surface 3S adapted to cooperate with the nare-engaging projection 22 to clamp the flared end of a pipe between them when the sleeve is threaded into the cavity 23. At its rear end the sleeve 32 has a projection 36 adapted to engage a wrench, and provided lwith a number of lateral threaded apertures for receiving set screws 3l.

In using this form `of fitting, the sleeve 32 is positioned on the end of the pipe 33 with the end portion thereof projecting from the bore at the leading end of the sleeve, adjacent the flareengaging surface 3b. he projecting end of the pipe is of the proper length to form the desired flare in making the connection. The set screws 3l are tightened against the pipe S3 so as to anchor the sleeve securely thereon. 'Ihe sleeve 32 is then threaded into the cavity of fitting 2l whereby the projecting end portion of the pipe is forced to ride up over the conical pro jection 29 at the base of the cavity 22, faring the pipe; and the resulting iia-re formed is then clamped between conical surface 35 and the conical projection 22, forming a leaktight connection between the pipe 33 and fitting 2T.

In this coupling, rotation of the pipe occurs during the making up of the coupling for nareforming operation thereof. If this is impractical in carrying out the installation, the same operations may be carried out before securing the ntting 21 in the orifice of the passage i3 so that in eifect the coupling members constitute a flareforming tool. Thereupon the set screws 3T are loosened or removed, and the coupling is eniployed in the same manner as is usual for preflared pipe. Since the sleeve 32 is no longer anchored to the pipe, it is adapted to rotate relative thereto, and in making up the connection the pipe does not rotate.

The coupling shown in Fig. 4 is similar in operation to that shown in Fig. 3, except that the female fitting 2 and male coupling member 32 of Fig. 3 are replaced in Fig. 4 by a male fitting 38 and a female coupling member 39. The fitting 38 is similar in construction to the fitting Ill of Figs. 1 and 2, and is similarly secured in the orince of a passage in a structure I4. Its leading end Iportion has external threads 40 and a conical flare-engaging projection 4l. The opposite coupling member or nut 39 has a bore 42 for slidably receiving a length of ductile pipe 43 and comprises a cavity 44 with internal threads 45, and a conical nare-engaging surface 46 at the inner end thereof Where it joins the rearwardly extending bore 42. Intermediate the ends of the bore, the nut 39 has a plurality of threaded lateral apertures 41 for receiving set screws 48.

In using this form of coupling, the nut 39 is placed over the end of the pipe 43 with a portion of the latter projecting from the inner end of the bore 42, adjacent the conical flare-engaging surface 46. Set screws 48 are tightened to anchor the nut 39 to the pipe, and the nut is then threaded onto the leading end portion of the fitting 38. The projecting end portion of the pipe 43 is thereby forced to ride up over the conical surfact 4l on the leading end of fitting 38 and is flared thereby. Finally, the flared portion of the pipe is clamped between conical surface 46 of the nut 39 and the conical projection on the fitting forming a leaktight joint between the pipe 43 and said fitting.

In this form of coupling, when used in the foregoing manner, it is likewise necessary that the usual manner for connecting pre-ared ductile pipe.

Variations and modifications may be made within the scope of this invention and portions of the improvements may be used without others.

I claim:

1. A coupling for threadless ductile metal tubing comprising a body member having a flareforrning and flare-seating conical projection having the diameter of its outwardly facing small end not greater than the internal diameter of the tubing, a draft member having screw thread engagement with the body member, and a sleeve connected to the draft member to travel therewith toward the body, said sleeve having a bore slidably receiving the end of the tubing and having a conical seat facing and conforming to the shape of said conical projection on the body, said sleeve having at least one setscrew positioned to engage the tubing for mechanically coupling the sleeve to the tubing therein for advancement therewith with the end of the tubing projecting a determinate distance beyond the seat on the sleeve, whereby when the draft member is advanced the projecting end of the tubing is extruded over the conical projection on the body and clamped between the latter and the conical seat on the end of the sleeve.

2. The invention as defined in claim 1, in which the sleeve is integral with the draft member and the setscrew on the sleeve is accessible for operation while the draft member and body are joined.

3. The invention as defined in claim 1, in which the sleeve is rotatably and slidably mounted in the draft member whereby the sleeve is positioned and secured to the tubing before the draft member is screwed onto the body member.

STEPHEN GUARNASCIIELLI.

REFERENCES CITED The following references are of record in the file of this pat-ent:

UNITED STATES PATENTS Number Name Date 515,893 Baily Mar. 6, 1894 802,853 Gardner and Davis Oct. 24, 1905 1,774,841 Parker Sept. 2, 1930 2,128,459 Guarnaschelli Aug. 30, 1938 2,466,057 Somma Apr. 5, 1949 FOREIGN PATENTS Number Country Date 548,029 Germany Apr. 6, 1932 

